feat(runtime-fallback): add configurable session timeout controls

src/hooks/runtime-fallback/constants.ts

@@ -14,6 +14,7 @@ export const DEFAULT_CONFIG: Required<RuntimeFallbackConfig> = {
   retry_on_errors: [400, 429, 503, 529],
   max_fallback_attempts: 3,
   cooldown_seconds: 60,
+  timeout_seconds: 30,
   notify_on_fallback: true,
 }
 

src/hooks/runtime-fallback/types.ts

@@ -58,6 +58,8 @@ export interface RuntimeFallbackOptions {
   config?: RuntimeFallbackConfig
   /** Optional plugin config override (primarily for testing) */
   pluginConfig?: OhMyOpenCodeConfig
+  /** Optional session-level timeout override in milliseconds (primarily for testing) */
+  session_timeout_ms?: number
 }
 
 export interface RuntimeFallbackHook {